Comparison of CMOS and BiCMOS 1-Mbit DRAM performance

The advantage of BiCMOS technology over CMOS technology in terms of the access time and the power dissipation is demonstrated for a 1.3- mu m 1-Mb DRAM with a TTL (transistor-transistor logic) interface. Two key results are obtained. One is that a BiCMOS driver achieves a 23% lower delay time and 28% lower power dissipation compared with a CMOS driver. This is due to the inherently small input gate capacitance of the BiCMOS inverter and the small number of inverter stages required to make the BiCMOS driver. The other result is that a 1-Mb BiCMOS DRAM incorporating the BiCMOS driver provides higher performance in terms of a 36% faster access time and 24% lower power dissipation after fabrication process deviations and temperature changes. The resistance to the process deviations and temperature changes of the BiCMOS is responsible for such excellent performance.>